My Holden (GM) Astra, built April 1999, has the same problem: I replaced the remote battery but the re-synchronising procedure does not work. I followed the procedure in the Owner's Handbook but the remote does not re-synchronise even after several minutes in the ignition at the 'II' position. The remote appears to have power: pressing either of its two buttons causes the red LED to flash.

Is the remote sensor pick-up in the car defunct?

Peter Lyons, March 2007

all you have to do is sit in the car with all the doors shut, put the key into the ignition turn it to on (not start the position before start) then off six times leaving in the on position on the sixth time then press the lock/unlock button on the remote heads.. IMPORTANT NOTE: this puts the car into learn mode and all remote heads have to be present eg if you have two both wil need to be retrained by pressing the unlock/unlock button. i have used this method on astras vectras and zafrias. also works on opel and vauxhall as there made by the same company

Dan, June 2008